Stabilizing roller

ABSTRACT

A stabilizing roller, especially for a raise boring head, in which an outer sleeve having cemented hard metal carbide elements inserted therein is mounted by an anti-friction bearing arrangement on a massive central shaft. The stabilizing roller is adapted for being disposed vertically at the periphery of a raise boring head for guiding the head during cutting operations.

United States Patent 91 [11] 3,797,592 Goodfellow 1 1 Mar. 19, 1974 1 STABILIZING ROLLER 3.659.660 5/1972 Conn 175/53 3.752.243 8/1973 Hummer et a1.... 175/372 [75] Invenmr when Bedford- 3.216.513 11/1965 Robbins et a1 175/372 x [73] Assignee: Kennarnetal lnc., Latrobe. Pa.

- Primarv Examiner-Ernest R. Purser 2 Fl (1: N .21, 1972 [2 1 1 e M Attorney, Agent, or Firm-Melvin A. Crosby [21] Appl. No.: 308,411

57] ABSTRACT [52] US. Cl 175/32'5,175/53, 175/346. I

174/364 175M105 308/4 A A stab1l1zmg roller, especially for a raise bormg head. 51 1111. C1 E2lb 17/10 in which Outer sleeve having cemented hard metal [58 Field of Search .L 175/53, 345-347. carbide elements inserted therein is mounted by an 75 3 3 3 4; 372 325 0. 3 /4 A 2 anti-friction bearing arrangement on a massive central shaft. The stabilizing roller is adapted for being dis- [56] References Cited posed vertically at the periphery of a raise boring head UNITED STATES PATENTS for guiding the head during cutting operations. 3.303900 7 Claims, 2 Drawing Figures 2/1967 Kloesel et a1. 175/339 .26 64 6s 66 6a 64 P/ 60 56 62 54 5 48 48 46 35 42 44 42 3s 46 B 34 34 I 32 32,11 I 36 36 LLLiiii 29 11111'1' i 6 a a,a.i.

STABILIZING ROLLER The present invention relates to a stabilizing roller,

especially for a raise boring head.

Raise boring heads are employed for reaming or enlarging holes drilled into earthen formations. For example, a fairly small hole, say, up to ten inches in diameter, can be drilled in a formation, for example, in the downward direction, until it intersects a passage and, thereafter, the cutter on the end of the drill string is removed and a raise boring head is .attached to the drill string. Such a raise boring head might be, for example, from six to ten feet in diameter and will enlarge the small drilled hole when the raise boring head is rotated and pulled upwardly along the axis of the drilled hole.

A raise boring head of the nature referred to has cutters distributed thereover in the radial and circumferential direction in the form of rolling cutters and which roll on the formation and thereby reduce the formation with the removed material dropping downwardly through the shaft to the bottom of the passage from which place it can readily be removed.

Formations worked in the foregoing manner will vary considerably in respect of the hardness and the distribution of rocks therein and the like and, as a natural consequence of rotating the raise boring head while pulling it upwardly against the formation, the rotary head is subjected to lateral forces which vary in magnitude and direction during the working operation.

Such lateral forces cause deflection of the raise boring head and the drill string and can lead to failure of the drill string or detachment of the raise boring head therefrom, whereupon the raise boring head-could drop downwardly in the shaft. An occurence of this nature is quite serious and expensive.

Furthermore, lateral movement of the raise boring head while working will cause thedrill string to engage the sides of the originally drilled hole which will cause wear on the drill string and can induce early failure thereof. The drill string is made up of interconnected lengths of pipe and is quite expensive and, in the normal course of events, is used over and over so that any wearing of the drill string is undesirable.

With the foregoing in mind, the primary object of the present invention is the provision of a stabilizing roller for mounting on a -raise boring head which will substantially eliminate, or at least greatly reduce, the amount of lateral movement of a raise boring head during working operations.

Another object of the present invention is the provision of a stabilizing roller of the nature referred to which is extremely strong and which will, thus, be able to counteract even strong lateral forces acting on the raise boring head.

A still further object of the present invention is the provision of a stabilizer roller of the nature referred to which can readily be restored to operating efficiency once the outer surface becomes worn.

These and other objects and advantages of the present invention will become more apparent upon reference to the following detailed specification taken in connection with the accompanying drawings in which:

FIG. 1 is a sectional view somewhat schematically illustrating a typical raise boring head and showing at the right side a stabilizer roller according to the present invention.-

FIG. 2 is an enlarged view of the stabilizer roller partly in section to show the internal construction thereof.

BRIEF SUMMARY OF THE INVENTION According to the present invention, a stabilizer roller, especially adapted for use with a raise boring head, is constructed by forming a massive central shaft element and mounting a relatively thin outer sleeve on the shaft element by means of antifriction bearings, specifically, roller bearings, and sealing the interior of the stabilizer roller against the ingress of dust and grit. The outer sleeve is provided with inserted cemented hard metal carbide wear elements which are distributed circumferentially and axially thereof and the sleeve element can be replaced when it becomes worn.

The stabilizer rollers are mounted at points spaced circumferentially about the raise boring head and are disposed on vertical axes and are radially positioned to engage the periphery of the shaft which is formed by the raise boring head as it is rotated and drawn upwardly through a formation.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings somewhat more in detail, the rolling cutter head illustrated in FIG. 1 comprises a central shaft 10 adapted for being secured to the lower end of drill string 12. Drill string 12 extends through a hole 14 drilled in formation 16 by a smaller cutter previously mounted on the lower end of the drill string and which was removed prior to mounting -the raise boring head thereon.

Central shaft 10 has plate means 18 mounted thereon in axially distributed relation and forming a structure for receiving saddles 20 in which rolling cutters 22 are rotatably supported. Rolling cutters 22 are distributed radially and circumferentially of the raise boring head and are preferably inclined at different angles to the axis thereof and provide for working engagement with substantially the entire area of the surface to be worked. No specific type of rolling cutter is illustrated, and it will be understood that these members could take any of several forms known in the art.

The rolling cutter head is adapted to form a shaft 24 in formation 16 as the rolling cutter head is rotated and pulled in the upward direction. According to the pres- I shaft 24 as the raise boring head moves upwardly therein.

The nature of a stabilizer roller according to the present invention will best be seen in FIG. 2, wherein it will be seen that the stabilizer roller comprises a massive central shaft 30 having reduced diameter portions 32 at the opposite ends on which end caps 34 are mounted and which end caps are held in position by cap screws 36 extending through holes in the end caps and threaded into the reduced diameter portions 32 of shaft 30.

Mounted on the larger central part of shaft 30 are the inner races 38 pertaining to an antifriction roller bearing which has a single elongated outer race 40 with two sets of rollers 42 interposed between inner races 38 and the double outer race 40. A spacer element 44 is interposed between the opposed inner ends of races 38.

Rings 46 surround the central portion of shaft 30 at the ends and have axially inner ends engaging the axially outer ends of races 38 while the axially outer ends of rings 46 engage the axially inner sides of end caps 34. The rings 46 provide for fixedly locating the inner races 38 on shaft 30 when cap screws 36 are pulled up tight.

The end caps 34 have axial flanges 48 partly coextensive with the respective rings 46 and seal elements 50 are interposed between flanges 48 and rings 46. Each seal element 50 comprises sealing material 52 and a metal carrier 54 with each carrier 54 having an axial flange which telescopically engages the respective axially outer end portion 56 of outer race 40.

For the purpose of tightly sealing the interior of the assembly against the ingress of grit and the like, rubberlike sealing O-rings 58 are mounted in annular grooves in reduced diameter portions 32 while further resilient annular O-rings 60 are mounted in grooves provided on the insides of flanges 48 of the end caps. Sealing rings 60 engage the metal outer parts 54 of the seal elements 50 which engage rings 46.

Mounted on outer race 46 is the outer sleeve part 62 of the rolling cutter and which is axially located on outer race 40 as by snap rings 64 seated in annular grooves formed on the inside of sleeve portion 62 and engaging the axially outer ends of outer race 40. The axially outer ends of sleeve portion 62 have a close running fit with the axially inner ends of the flanges 48 of the respective end caps 34.

Sleeve portion 62 is provided with substantially radial holes or recesses distributed over the periphery thereof and mounted in these holes, or recesses, are the button elements 66 formed of a hard wear resistant material such as cemented hard metal carbide and preferably cemented tungsten carbide. These button elements, which are rod-like members with rounded outer ends, may be press fitted, cemented, or brazed into the holes, or recesses, 68 provided therefore and impart abrasion resistant characteristics to sleeve portion 62 so that the stabilizer roller can remain in service for a prolonged length of time.

It is not intended that the stabilizer roller carry out any cutting operations, but it is, nevertheless, the case that the hard carbide buttons projecting from the cylindrical outer periphery of sleeve portion 62 will reduce any part of the wall of the shaft being formed should the stabilizer roller be'forceably thrust against the shaft wall.

In normal operations, however, the stabilizer rollers will merely roll on the wall of the shaft being formed and will prevent any substantial amount of lateral movement of the raise boring head relative to the axis of the shaft. The principle force exerted on the raise boring head is in the upward direction toward the formation and, accordingly, there is no working force directed laterally that is sustained by the stabilizer rollers.

The lateral forces exerted on the raise boring head due to boring operations, however, can, at times, become extremely high. The stabilizer roller according to the present invention, with the massive central shaft and the large anti-friction bearing that supports the outer sleeve portion on the central shaft, has been found to be highly efficient in sustaining such lateral thrusts.

The stabilizer roller can be quite simply mounted on the structure of the raise boring head by availing of saddle means 70 of substantially any conventional type.

Modifications may be made within the scope of the appended claims.

What is claimed is: y

1. In a stabilizer roller, especially for mounting on a vertical axis at the periphery of a raise boring head; a massive shaft having a central region and reduced diameter end parts, a cylindrical sleeve surrounding said central region, end caps fixedly connected to said end parts and telescopically engaging the end portions of said sleeve, and antifriction bearing means supporting said sleeve on said central region of said shaft and clamped between said end caps.

2. A stabilizer roller according to claim 1 in which said sleeve is provided with radial bores distributed axially and circumferentially thereout, and elements of hard wear resistant material fixed in said radial bores and protruding therefrom toward the outsides of said sleeve. i

3. A stabilizer roller according to claim 2 in which said elements are formed of a cemented hard carbide material.

4. A stabilizer roller according to claim 3 in which said carbide material is tungsten carbide.

5. A stabilizer roller according to claim 1 in which said'bearing means comprises inner race means fitted on said central region of said shaft, outer race means fitted into said sleeve, and rolling elements fitted between said race means, a clamp ring clamped between each end cap and the adjacent end of said inner race means, a seal element sealingly engaging the radially outer side of each ring and each having a metal carrier engaging the adjacent end of said outer race means, a seal ring between each end cap and the adjacent metal carrier and a further seal ring between each end cap and the respective reduced diameter part of said shaft.

6. A stabilizer roller according to claim 1 in which said bearing means comprises a single elongated outer race and a pair of axially spaced inner races and rollers between each inner race and the outer race, means holding said sleeve against axial movement on said outer race, a clamp ring clamped between each end cap and the axially outer end of the adjacent inner race, a seal element sealingly engaging the radially outer side of each clamp ring, a metal carrier for each seal element having an axial flange telescopically engaging the inside of the adjacent end of said outer race, and resilient O-rings in each end cap engaging the radially outer sides of the adjacent metal carrierand the adjacent end part of said shaft.

7. A stabilizer roller according to claim 1 in which each end cap has an axial portion adapted to be clamped in a support saddle. 

1. In a stabilizer roller, especially for mounting on a vertical axis at the periphery of a raise boring head; a massive shaft having a central region and reduced diameter end parts, a cylindrical sleeve surrounding said central region, end caps fixedly connected to said end parts and telescopically engaging the end portions of said sleeve, and antifriction bearing means supporting said sleeve on said central region of said shaft and clamped between said end caps.
 2. A stabilizer roller according to claim 1 in which said sleeve is provided with radial bores distributed Axially and circumferentially thereout, and elements of hard wear resistant material fixed in said radial bores and protruding therefrom toward the outsides of said sleeve.
 3. A stabilizer roller according to claim 2 in which said elements are formed of a cemented hard carbide material.
 4. A stabilizer roller according to claim 3 in which said carbide material is tungsten carbide.
 5. A stabilizer roller according to claim 1 in which said bearing means comprises inner race means fitted on said central region of said shaft, outer race means fitted into said sleeve, and rolling elements fitted between said race means, a clamp ring clamped between each end cap and the adjacent end of said inner race means, a seal element sealingly engaging the radially outer side of each ring and each having a metal carrier engaging the adjacent end of said outer race means, a seal ring between each end cap and the adjacent metal carrier and a further seal ring between each end cap and the respective reduced diameter part of said shaft.
 6. A stabilizer roller according to claim 1 in which said bearing means comprises a single elongated outer race and a pair of axially spaced inner races and rollers between each inner race and the outer race, means holding said sleeve against axial movement on said outer race, a clamp ring clamped between each end cap and the axially outer end of the adjacent inner race, a seal element sealingly engaging the radially outer side of each clamp ring, a metal carrier for each seal element having an axial flange telescopically engaging the inside of the adjacent end of said outer race, and resilient O-rings in each end cap engaging the radially outer sides of the adjacent metal carrier and the adjacent end part of said shaft.
 7. A stabilizer roller according to claim 1 in which each end cap has an axial portion adapted to be clamped in a support saddle. 